The present invention relates to a cooling device of an electronic apparatus with using a liquid as a cooling means for heat-generating parts thereof.
An electronic apparatus, such as a computer, for example, generates heat when it operates.
In particular, heat generation of highly integrated semiconductor device rises up in an amount thereof, in recent years. However, since the semiconductor device will loose the function as it is, when exceeding a certain temperature, therefore it is necessary to conduct cooling thereon effectively.
As a means for cooling the semiconductor device in the electronic apparatus, those are already known, such as, a natural cooling system through a phenomenon, the heat conduction, a compulsive air cooling system by means of a fan, or a liquid cooling system with using a heat pipe therein, for example.
In the natural cooling system, the cooling is achieved by using a material having a large heat conductivity within a heat radiation path reaching from the semiconductor device to an outside of the electronic apparatus.
This method is suitable for use in the semiconductor device having a relatively small amount of heat generation, or for the electronic apparatus, being compact in the size, such as, a personal computer of note-type or the like, for example.
In the compulsive air cooling system by means of a fan, etc., the air-blowing device is provided within the electronic apparatus, thereby generating the convection, compulsively, for cooling the semiconductor device provided therein.
Since being suitable for use in cooling of the semiconductor, which has an amount of heat generation up to a certain degree thereof, this method is widely used, in general, and is also applied into a personal computer with making the air-blowing device small in the sizes and thin in the thickness thereof.
In the cooling of using the heat pipe therein, the heat of the semiconductor element is transferred by the function of coolant, which is enclosed within a pipe.
The conventional technology of using such the heat pipe is described, for example, in Japanese Patent Laying-Open No. Hei 1-84699 (JP-A 84699 (1989)) and Japanese Patent Laying-Open No. Hei 2-244748 (JP-A 244748 (1990)).
With those conventional technologies, though being extremely high in the effect of saving electric power since there is used no portion, consuming the electric power therein, however there is a limit an amount of heat, which can be transmitted therewith.
Now, a technology is practiced, conventionally, cooling the semiconductor device generating heat through circulation of a liquid coolant thereto; thus, water, by means of a pump, etc., for example. Such the cooling means is applied into a large-scale computer dealing a large amount of data, for use in a bank and/or a company, etc., for example.
For this conventional technology, relating to a cooling method by means of the liquid coolant, the following can be listed up; Japanese Patent Laying-Open No. Hei 5-335454 (JP-A 335454 (1993)), Japanese Patent Laying-Open No. Hei 6-97338 (JP-A 97338 (1993)), and Japanese Patent Laying-Open No. Hei 6-125188 (JP-A 125188 (1994)), for example.
However, those conventional technologies are limited to the large-scale computer, in uses thereof.
The reason of this lies in that the apparatus as a whole comes to be large in the sizes since the liquid cooling system needs a large number of parts for exclusive use of cooling, such as a pump, a piping system, a heat exchanger(s), etc., and that it is difficult to ascertain a reliability for safety, comparing to other methods, due to use of the liquid for the purpose of cooling.
Also, one of the other reasons lies in the fact that the semiconductor device, having such large heat generation that it needs the liquid cooling, is not used, but only in the large-scaled computer.
As the conventional arts, applying such the liquid-cooling technology for the large-scale computer into a small size electronic apparatus (such as, the note-type personal computer), the followings can be listed up, for example, Japanese Patent Laying-Open No. Hei 6-266474 (JP-A 266474 (1994)), and Japanese Patent Laying-Open No. Hei 7-142886 (JP-A 142886 (1995)).
In such the conventional arts, which are described in the Japanese Patent Laying-Open No. Hei 7-142886 (JP-A 142886 (1995)) and the Japanese Patent Laying-Open No. Hei 6-266474 (JP-A 266474 (1994)), an improvement is made on the reliability, in particular with respect to the heat conductivity and the liquid leakage, by applying a heat receiving jacket, a heat radiation tube and a metal heat exchanger therein. However, in those conventional arts, the heat receiving jacket and the heat radiation tube are made of metal, by taking the heat conductivity thereof into the consideration.
On a while, the heat receiving jacket is preferable in a plate-type, from the consideration of the heat conductivity thereof, therefore it is necessary to form flow passages made up with a minute fin structure in the heat-receiving jacket of such the plate-type. The minute fin structure of the heat receiving jacket can be manufactured with relative ease.
Accordingly, for such the plate-type heat receiving jacket, aluminum is preferable to form, from the viewpoints, such as, the heat transfer performance, the cost and the processability thereof, while a copper pipe is preferable for the heat radiation pipe and the heat exchanger from the viewpoints, such as, the heat transfer performance, the cost and the processability thereof.
However, when adopting a combination of the heat receiving jacket made of aluminum, the heat radiation pipe and the heat exchanger, both made of copper, being preferable from the viewpoints, such as, the heat transfer performance, the cost and the processability, then there is a problem that the localized corrosion (or pitting corrosion, crevice corrosion) of the aluminum is accelerated remarkably, due to copper ion dissolved from the copper.
Also, from a tube made of a polymeric material group, which is adopted to be a connector tube, corrosive ion is dissolved, including halogen ion therein, for example; therefore, the localized corrosion is further accelerated, remarkably.
An object, according to the present invention, is to provide an electronic apparatus, with which an improvement can be obtained on reliability, in particular when being mounted with a cooling device combining the copper and the aluminum.
For accomplishing the object mentioned above, according to the present invention, firstly, there is provided a cooling device for an electronic apparatus, comprising: a heat generating element attached within a housing; a heat receiving jacket, being connected with said heat generating element; a first heat exchanger for exchanging heat between an outside; and a liquid driving means for supplying a liquid to said heat receiving jacket, wherein a part of pipework connecting between said heat receiving means, said first heat exchanger, and said liquid driving means is made from a flexible tube of resin, and further comprising, a second heat exchanger and an ion exchanger, which are provided in a part of said pipework.
Also, according to the present invention, in the cooling device for an electronic apparatus, as described in the above, wherein said ion exchanger absorbs therein a corrosion inhibitor in advance, and said cooling liquid is added with a corrosion inhibitor therein.
And, also according to the present invention, in the cooling device for an electronic apparatus, as described in the above, wherein said heat receiving jacket is made of an aluminum group material, said second heat exchanger is made of a copper group material, said liquid medium is an anti-freezing liquid or a pure water, and into said cooling liquid is added a corrosion inhibitor for the copper group material.
Further, according to the present invention, for also achieving the object mentioned above, there is also provided a cooling device for an electronic apparatus, comprising: a heat generating element attached within a first housing; a heat receiving jacket, being connected with said heat generating element, and being attached within said first housing; a second housing being rotatably supported on said first housing; a first heat exchanger attached within said second housing, for exchanging heat between an outside; and a liquid driving means for supplying a cooling liquid to said heat receiving jacket, wherein a portion of a pipe for connecting between said heat receiving means, said first heat exchanger, and said liquid driving means is made of a flexible tube made of a resin, and further wherein, a second heat exchanger and an ion exchanger are provided in a part of said pipe, said second housing is received within said second housing, and said ion exchanger is received within said second housing.
Also, according to the present invention, in the cooling device for an electronic apparatus, as described in the above, wherein said second heat exchanger is cooled by means of a fan.
And also, according to the present invention, in the cooling device for an electronic apparatus, as described in the above, wherein said ion exchanger absorbs therein a corrosion inhibitor in advance, and said cooling liquid is added with a corrosion inhibitor therein.
Furthermore, according to the present invention, in the cooling device for an electronic apparatus, as described in the above, wherein a display device made from a liquid crystal panel is provided in said second housing, and said ion exchanger is provided on a reverse side surface of said liquid crystal panel.